My research is focused on understanding the mechanism for electroweak symmetry breaking (EWSB). In the Standard Model (SM), symmetry is broken by the introduction of a postulated Higgs field. While the SM has been extensively tested, there is still no direct evidence for the simple Higgs mechanism as origin for EWSB. There are other appealing concepts, such as supersymmetry (SUSY), offering mechanisms for EWSB, but so far none have been proven valid experimentally. The facilities that can address these problems are the Tevatron and the LHC. My physics interests at the Tevatron include searches for Higgs boson and detailed studies of top quark properties with Run II data. I am a member of the D0 collaboration since 2000. Before 2007, the Tevatron is the unique machine providing the data which might shed light on the origin of the mass and is the only place to study top quarks. The top quark is the only fermion with a mass on the EWSB scale, so it is an excellent probe of the EWSB sector, fermion mass generation, and the possible existence of other massive particles. My particular interests are precise measurements of the top quark production cross section and top quark properties. For the search of top quark signal one of the most powerful tools against background is b-quark jet identification (b-tagging). So I am working on the development of the b-tagging algorithms and on their calibration on data. ATLAS experiment will start to work in 2007. Physicists hope that new particles and new phenomena will be discovered at the LHC. These discoveries will bring us to the next step of the understanding of our Universe. I will continue to search for the Higgs boson and to perform a precise measurements of the top quarks. I am involved in the development of the b-tagging, alignment of the current pixel tracking system at the ATLAS experiment. I am also working on the upgrade of the pixel tracker.